The Master Lock No. 4400EC Bluetooth® Padlock features a 1-29/32in (47mm) wide metal body for durability. The 9/32in (7mm) diameter shackle offers 7/8in (22mm) vertical clearance and is made of boron alloy, offering maximum resistance to cutting and sawing. Secure your home or business with the Master Lock Vault System for unmatched security, simplicity and accountability using the latest in Bluetooth lock technology from Master Lock. These locks withstand physical attacks and hacks, protecting your property with military grade encryption and high-security features. Administrators control individual or system-wide lock access with our convenient app and web interface options, while users enjoy simple, secure access to assigned locks or lock boxes.

• Use your smartphone to open and manage your lock with the Master Lock® Vault System compatible with both Master Lock Vault Home and Master Lock Vault Enterprise.
• The free Master Lock Vault Home iOS and Android apps are designed for personal use, supporting up to 10 locks, allowing you to monitor access history and includes a Locker Mode setting that allows for storage inside a locker.
• The free Master Lock Vault Enterprise iOS and Android app and web interface are designed for business applications working with many locks and many users allowing you to easily monitor access with robust data and audit trails.
• No keys to lose, no combinations to forget. No unauthorized key duplication.
• Share access with others - temporary or permanent.
• Backup access using directional code on lock keypad.
• Low battery notification & reminder on padlock and in app.
• Comes with easy to replace CR2450 battery.
• Battery jump allows for temporary access if battery dies while locked.